Endovascular grafts have been developed to treat patients with arterial lesions, particularly, aneurysms, trauma and arterial dissections, from within the arterial tract to reduce morbidity and mortality associated with the arterial disorder. Application of the graft is typically performed in conjunction with a minimally invasive operative procedure to minimize patient trauma, recovery time, etc.
A variety of endovascular grafts are currently on the market or in clinical trails. These grafts have a number of different characteristics related to their fixation mechanisms, construction and support with respect to the vessel wall. Currently, fixation of the endovascular graft can be achieved through radial wall tension using a self expanding stent or by balloon expansion of a deformable stent which may possess fixation elements to penetrate the arterial wall. Alternatively, the stent/graft may be secured to the vessel wall through suturing.
U.S. Pat. No. 4,787,899 to Lazarus discloses an intralumenal grafting system for placement of a hollow graft in a corporal lumen. The '899 system incorporates a cylindrically shaped graft having a plurality of hook-like staples embedded in the graft. Once the graft is positioned with the desired location in the vessel, an inflation member is expanded to drive the staple legs through the vessel wall thereby securing the graft to the vessel wall.
However, known graft deployment systems such as the type disclosed in the '899 patent are subject to several disadvantages which detract from their usefulness in vascular graft securement. Graft migration subsequent to deployment and leakage about the staple-vessel wall juncture, sometimes in the order of 20-30%, are typical with such systems. In addition, the graft with fixed staple arrangement is deficient in conformational changes which may occur after grafting. With modular grafts, i.e., multiple element grafts connected to each other, late disruption at the connection between the components is also prevalent.